887 research outputs found

    BUSINESS GROWTH STRATEGIES OF ILLINOIS FARMS: A QUANTILE REGRESSION APPROACH

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    This study examines the business strategies employed by Illinois farms to maintain equity growth using quantile regression analysis. Using data from the Farm Business Farm Management system, this study finds that the effect of different business strategies on equity growth rates differs between quantiles. Financial management strategies have a positive effect for farms situated in the highest quantile of equity growth, while for farms in the lowest quantile the effect on equity growth is negative. Cost reduction, asset management and revenue enhancement strategies all proved to have important effects on the determination of growth equity rates.Farm Management,

    The Origin of Xenoliths with Cumulus Textures Found Above the Subsurface Extension of the Stillwater Complex, Montana

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    The Archean Stillwater Complex is a large layered mafic-ultramafic intrusion (LMI) exposed in the Beartooth Mountains of south-central Montana. Gravity measurements suggest that the north-dipping complex extends under cover at depth. Some of the exposures located above the subsurface Stillwater Complex are younger Cretaceous stocks (Susie Peak and Sliderock Mountain stocks), diorite sills and andesite dikes, exposed north of the complex, passed through area of the gravity anomaly that may be the Stillwater Complex. In the summer of 2013, samples of the stocks and their included xenoliths (foreign rock fragments; commonly metamorphosed to greenschist facies conditions) were collected for study. Xenoliths with textures reminiscent of Stillwater Complex cumulates were chosen for further investigation. The host andesitic rocks containing the xenoliths exhibit porphyritic textures—phenocrysts of plagioclase, amphibole ± biotite occur in a finer-grained groundmass of the same minerals. Electron microprobe analyses of amphibole grains from both the host and xenolith are comparable in composition. Electron microprobe analyses for two samples of coexisting xenolith amphibole (Tschermakitic hornblende, magnesio-hastingsite) and plagioclase (rim An83-91Ab17-9) constrain temperature conditions at various pressures (P at 3, 5, and 6 kb; T = 500-656°C, respectively using Holland and Blundy (1994). These conditions are consistent with amphibolite facies metamorphism. Few xenoliths retain the original igneous mineralogy (with the exception of plagioclase) but one sample contains relict “Stillwater-like” mineralogy (e.g., clinopyroxene) and another contains chromite. Plagioclase and relict clinopyroxene compositions are somewhat comparable to Stillwater mineral compositions. The fact that the xenoliths are now metamorphosed and highly altered suggests that either they were metamorphosed prior to their inclusion in the melt or were metamorphosed or hydrothermally altered as a result of incorporation into the melt

    Metro Habitat Connectivity Toolkit: Bringing Connectivity to an Actionable Scale

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    Habitat fragmentation is a serious threat to maintaining biodiversity particularly in urbanizing areas. Methods exist to model habitat connectivity, however many of these are applied at large scales and rely on data that may be a decade or older, resulting in inaccuracies when compared to on the ground conditions, particularly in dynamic urban systems that experience rapid change. These issues make taking action to preserve or enhance these connectivity zones difficult, if not impossible. The Metro Regional Habitat Connectivity Toolkit approaches this problem by combining GIS analysis with on the ground assessments at realistic scales for land acquisition, restoration projects and/or barrier mitigation. We employed a surrogate species approach to address connectivity needs in a way that incorporates empirical data. Local information and research was combined with other habitat attributes to focus development of field assessments for habitat quality and barrier permeability. The field assessments allow technicians to verify GIS data, identify barriers and record habitat attributes in a way that is comparable across multiple habitat connectivity zones and for multiple species. Once assessments are concluded the resulting information is used to generate two species specific scores for habitat quality and barrier permeability. These scores identify where on the landscape restoration and/or land acquisitions would provide the most connectivity benefit vs areas where mitigation for barriers such as wildlife passages structures across roads are the priority. This toolkit is in the final stages of development and is currently being testing in pilot areas in the Portland Metro region

    Metro Habitat Connectivity Toolkit: Bringing Connectivity to an Actionable Scale

    Get PDF
    Habitat fragmentation is a serious threat to maintaining biodiversity particularly in urbanizing areas. Methods exist to model habitat connectivity, however many of these are applied at large scales and rely on data that may be a decade or older, resulting in inaccuracies when compared to on the ground conditions, particularly in dynamic urban systems that experience rapid change. These issues make taking action to preserve or enhance these connectivity zones difficult, if not impossible. The Metro Regional Habitat Connectivity Toolkit approaches this problem by combining GIS analysis with on the ground assessments at realistic scales for land acquisition, restoration projects and/or barrier mitigation. We employed a surrogate species approach to address connectivity needs in a way that incorporates empirical data. Local information and research was combined with other habitat attributes to focus development of field assessments for habitat quality and barrier permeability. The field assessments allow technicians to verify GIS data, identify barriers and record habitat attributes in a way that is comparable across multiple habitat connectivity zones and for multiple species. Once assessments are concluded the resulting information is used to generate two species specific scores for habitat quality and barrier permeability. These scores identify where on the landscape restoration and/or land acquisitions would provide the most connectivity benefit vs areas where mitigation for barriers such as wildlife passages structures across roads are the priority. This toolkit is in the final stages of development and is currently being testing in pilot areas in the Portland Metro region

    NASA CPAS Drogue Textile Riser Feasibility Study

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    Steel cable was chosen for the lower end of the drogue and main parachute risers on NASA's Orion Multi Purpose Crew Vehicle Parachute Assembly System (CPAS) to protect the risers from extreme temperatures and abrasion should they contact the crew module during deployment, as was done for Apollo. Due to the weight and deployment complexity inherent in steel, there was significant interest in the possibility of substituting textile for steel for the drogue and main parachute risers. However, textile risers could be damaged when subjected to high temperature and abrasion. Investigations were consequently performed by a subset of the authors to determine whether sacrificial, non-load-bearing textile riser covers could be developed to mitigate the thermal and abrasion concerns. Multiple material combinations were tested, resulting in a cover design capable of protecting the riser against severe riser/crew module contact interactions. A feasibility study was then conducted to evaluate the performance of the textile drogue riser cover in relevant abrasive environments. This paper describes the testing performed and documents the results of this feasibility study

    The ral exchange factor rgl2 promotes cardiomyocyte survival and inhibits cardiac fibrosis

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    Cardiomyocytes compensate to acute cardiac stress by increasing in size and contractile function. However, prolonged stress leads to a decompensated response characterized by cardiomyocyte death, tissue fibrosis and loss of cardiac function. Identifying approaches to inhibit this transition to a decompensated response may reveal important targets for treating heart failure. The Ral guanine nucleotide disassociation (RalGDS) proteins are Ras-interacting proteins that are upregulated by hypertrophic stimuli. The Ral guanine nucleotide dissociation stimulator-like 2 (Rgl2) is a member of the RalGDS family that modulates expression of hypertrophic genes in cardiomyocytes. However, the pathophysiologic consequence of increased Rgl2 expression in cardiomyoctyes remains unclear. To evaluate the effect of increasing Rgl2 activity in the heart, transgenic mice with cardiac-targeted over-expression of Rgl2 were generated. Although Ral activation was increased, there were no apparent morphologic or histological differences between the hearts of Rgl2 transgenic and nontransgenic mice indicating that increased Rgl2 expression had no effect on basal cardiac phenotype. To determine if Rgl2 modulates the cardiac response to stress, mice were infused with the ß-adrenergic receptor agonist, isoproterenol. Isoproterenol infusion increased heart mass in both Rgl2 transgenic and nontransgenic mice. However, unlike nontransgenic mice, Rgl2 transgenic mice showed no morphologic evidence of cardiomyocyte damage or increased cardiac fibrosis following isoproterenol infusion. Increased Rgl2 expression in cultured cardiomyocytes stimulated Ral activation and inhibited staurosporine-induced apoptosis via increased activation of PI3-kinase. Activation of the PI3-kinase signaling pathway was confirmed in hearts isolated from Rgl2 transgenic mice. Increased expression and function of Rgl2 in cardiomyocytes promotes activation of the PI3-kinase signaling cascade and protects from carciomyocyte death and pathologic cardiac fibrosis. Taken further, these results suggest that Rgl2 upregulation in hypertrophic hearts may be a protetive mechanism, and that Rgl2 may be a novel therapeutic target in treating heart disease

    Controlling TcT_c of Iridium films using interfacial proximity effects

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    High precision calorimetry using superconducting transition edge sensors requires the use of superconducting films with a suitable TcT_c, depending on the application. To advance high-precision macrocalorimetry, we require low-TcT_c films that are easy to fabricate. A simple and effective way to suppress TcT_c of superconducting Iridium through the proximity effect is demonstrated by using Ir/Pt bilayers as well as Au/Ir/Au trilayers. While Ir/Au films fabricated by applying heat to the substrate during Ir deposition have been used in the past for superconducting sensors, we present results of TcT_c suppression on Iridium by deposition at room temperature in Au/Ir/Au trilayers and Ir/Pt bilayers in the range of \sim20-100~mK. Measurements of the relative impedance between the Ir/Pt bilayers and Au/Ir/Au trilayers fabricated show factor of \sim10 higher values in the Ir/Pt case. These new films could play a key role in the development of scalable superconducting transition edge sensors that require low-TcT_c films to minimize heat capacity and maximize energy resolution, while keeping high-yield fabrication methods.Comment: 5 journal pages, 4 figure
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